Field of the Invention
The present invention relates to a shield drive device for a head lamp, and more particularly, to a shield drive device that opens and closes a shield to drive a high beam and a low beam in a bi-functional head lamp.
Description of Related Art
In general, an illumination device is installed in a vehicle in order to stably secure a view of a driver when surrounding illumination is low while driving.
A head lamp in the illumination device is primarily used to secure a stable visual distance of the driver.
In general, the head lamp may selectively irradiate a high beam and a low beam forward according to an irradiation angle and a light amount of light irradiated from a light source and the selective irradiation of the high beam and the low beam is performed by opening and closing operations of a shield by driver's operating a switch or automatically performed by the opening and closing operations of the shield according to a driving state of the vehicle.
FIGS. 6 and 7 are a side view, a perspective view, and a front view illustrating a shield drive device in the related art.
As illustrated in FIGS. 6 and 7, an actuator 110 that actuates a shield 130 is deployed below a lamp assembly 100, the shield 130 which is foldable by a lower end hinge structure is deployed in front of a light source (not illustrated), and a plunger 140 of the actuator 110 is connected to a lower end portion of the shield 130 together with a damper 150.
Herein, undescribed reference numerals 160 and 170 represent a shield spring providing force for automatic shield closing and a noise preventing damper, respectively.
Therefore, when the shield is maintained in a closed state, the low beam may be implemented (for example as shown in various embodiments of the present invention illustrated in FIG. 1) and when the shield is maintained in an opened state, the high beam may be implemented (for example as shown in various embodiments of the present invention illustrated in FIG. 2).
However, in the shield drive device in the related art, a plunger distortion phenomenon occurs due to generation of a height difference between the actuator and a shield connection unit when the shield is opened and closed, and as a result, there is a problem in that noise is generated when the shield is driven.
For example, as illustrated in FIG. 8, while the shield 130 is closed, centers of a plunger connection unit, the damper 150, and the shield connection unit coincide with each other, distortion does not occur, but as illustrated in FIG. 9, when the shield 130 rotates while the actuator 110 is driven, the shield 130 rotates around a rotational shaft and in this case, a height difference H is generated between the plunger connection unit and the shield connection unit to cause the damper 150 to be twisted and the plunger to be distorted and consequently, such a phenomenon results in generation of the noise.
That is, when the shield is opened by driving the actuator, large noise is not generated, but while applied voltage of the actuator is cut off, when the shield is closed by spring restoration force, the large noise is generated while the noise preventing damper and the shield collide with each other.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.